Data from: Signatures of human impact: size distributions and spatial organization of wetlands in the prairie pothole landscape

More than 50% of global wetland area has been lost over the last 200
years, resulting in losses of habitat and species diversity as well as
decreased hydrologic and biogeochemical functionality. Recognition of the
magnitude of wetland loss as well as the wide variety of ecosystem
services provided by wetlands has in recent decades led to an increased
focus on wetland restoration. Restoration activities, however, often
proceed in an ad-hoc manner, with a focus on maximizing the total restored
area rather than on other spatial attributes of the wetland network, which
are less well understood. In this study, we have addressed the question of
how human activities have altered the size distribution and spatial
organization of wetlands over the Prairie Pothole Region of the Des Moines
Lobe using high-resolution LIDAR data. Our results show that as well as
the generally accepted 90% loss of depressional wetland area, there has
been a disproportionate loss of both smaller and larger wetlands, with a
marked alteration of the historical power-law relationship observed
between wetland size and frequency and a resulting homogenization of the
wetland size distribution. In addition, our results show significant
decreases in perimeter-to-area ratios, increased mean distances between
wetlands, particularly between smaller wetlands, and a reduced likelihood
that current wetlands will be located in upland areas. Such patterns of
loss can lead to disproportionate losses of ecosystem services, as smaller
wetlands with larger perimeter-to-area ratios have been found to provide
higher rates of biogeochemical processing and groundwater recharge, while
increased mean distances between wetlands hinder species migration and
thus negatively impact biodiversity. These results suggest the need to
gear restoration efforts towards understanding and recreating the size
distribution and spatial organization of historical wetlands, rather than
focusing primarily on an increase in overall area.